Important Microorganisms Responsible for Dental Infections - Actinomycetes (?ctinomyces spp.)

The unequivocal role of microorganisms in the etiopathogenesis of periodontitis was established about 40 years ago. Endodontic infections develop after pulp necrosis or in cases where the pulp has been removed for the purposes of endodontic treatment. After pulp necrosis, bacteria colonizing the root canal system come into contact with the periradicular tissues of the tooth through the apical and lateral foramina. They can develop and propagate uninhibited by the defense mechanisms of the macroorganism by forming polymicrobial biofilms in the endodontium of the teeth, which leads to inflammation of the periradicular tissues. Actinomycetes (Actinomyces spp. ) in humans are part of the normal mucous microbiota of the oral cavity, the intestinal tract, and the urogenital tract in women. Actinomycetes have been isolated from tooth plaques, carious lesions (A. odontolyticus), tonsillar crypts, the pharynx. The infections caused by them are endogenous, with no evidence of person-to-person mode of transmission or origin from an exogenous source. Most actinomycotic infections are believed to develop in the area of the face and neck, in patients with poor oral hygiene or in such that have undergone invasive, surgical interventions (e. g. tooth extraction) or trauma. Actinomyces spp. have been isolated in 10 % of the cases of infected root canals, and mostly in those of them that have undergone failed primary endodontic treatment.